1. Field of the Invention
The invention relates to devices providing remote controls, such more particularly as the opening of a garage door, by means of coded signals transmitted in space without any material support.
2. The Prior Art
The invention relates more particularly, among these devices, to those comprising a portable case adapted to emit the coded signals and a receiver mounted on the member to be controlled and adapted to receive these signals, to compare them with a previously recorded reference and to provide the desired control when this comparison reveals identity between a coded signal received and the reference, this control being more especially the unlocking of the door followed by automatic opening of this door.
The advantages offered by remote control devices of this kind are known, which allow more especially motorists to operate the door of their garage without having to get out of their vehicle.
But the known devices of the kind in question present some disadvantages and in particular the following one: the remote control may be easily provided by means of the case by anyone carrying this case and even by those who have not received permission from the owner of said case, such as when said cases is stolen.
To remedy this disadvantage, it has already been proposed to equip the case in question with a keyboard comprising at least two control keys for forming on this case itself the coded remote control signal by a sequence of actuation of the keys of the keyboard in accordance with a predetermined code.
Only the persons who know this code can then effect with the help of the case considered the remote controls for which this latter is intended.
This solution thus protects the owner of the case from unauthorized use of this case.
Such an advantage is precious.
But it is offset by the following disadvantage: forming the code at the very time when the remote control is to be given effect is often irksome and relatively long, requiring in particular for handling the keyboard sufficient lighting and the complete freedom of both hands of the user, which in some circumstances is particularly troublesome, even at the outside prohibitive.